“Together with the well-established Th1 and Th2 effector subsets, Th17 cells are widely considered to be a third lineage of effector T helper cells. Since their discovery, a large body of evidence quickly grew that suggested a pathogenic role for these inflammatory cells in many mouse-models of autoimmune conditions, such as in experimental autoimmune encephalomyelitis (EAE) and Collagen-induced arthritis (CIA).

Our initial work assessed the ability of Th17 cells to be pathogenic in an adoptive transfer model of type one diabetes. We found that in vitro generated Th17 cells could transfer type one diabetes (T1D), but showed that this was due to their conversion to a Th1-like profile, and was dependent on the production of IFNg.

Following this work, some controversies have surfaced about the nature of Th17 cells in humans and in mice, about how they may be differentiated in vitro and around the lack of analysis of Th17 cells generated in vivo. We have used an epigenetic approach to analyse purified populations of Th17 cells generated in vitro and also in vivo (either naturally or in a model of intestinal inflammation involving infection with Helicobacter hepaticus) to further understand their apparent lineage flexibility.

The data presented will aim to resolve some of the controversies in the murine field of Th17 cells, whilst also speculating about what a Th17 cell may be, and what roles such cells may play in the immune system.”